Grand Tack Model

Definition

The Grand Tack model is a hypothesis that explains the formation and early evolution of the solar system. It proposes that the gas giant planets, particularly Jupiter and Saturn, underwent a complex inward-then-outward migration in the early stages of the solar system's development, significantly shaping the final architecture of the planets and their orbits.

5 Must Know Facts For Your Next Test

1. The Grand Tack model suggests that Jupiter initially migrated inward in the protoplanetary disk, disrupting the orbits of the inner solar system planets, before reversing its migration and moving outward.
2. The inward migration of Jupiter is believed to have cleared a gap in the protoplanetary disk, creating a barrier that prevented the inner terrestrial planets from accreting more material and growing larger.
3. The outward migration of Jupiter and Saturn is thought to have played a significant role in the final configuration of the solar system, including the formation of the asteroid belt and the orbital characteristics of the outer planets.
4. The Grand Tack model helps explain the relatively small sizes of the inner terrestrial planets, as well as the distribution of material in the asteroid belt and the Kuiper Belt.
5. The model also provides insights into the Late Heavy Bombardment, a period of increased impact cratering in the inner solar system, which may have been triggered by the migration of the gas giants.

Review Questions

• Describe the key stages of the Grand Tack model and how they shaped the formation of the solar system.
  • The Grand Tack model proposes that the gas giant planets, particularly Jupiter and Saturn, underwent a complex migration pattern in the early stages of the solar system's development. Initially, Jupiter is believed to have migrated inward in the protoplanetary disk, disrupting the orbits of the inner terrestrial planets and creating a gap that prevented them from accreting more material and growing larger. Later, Jupiter and Saturn are thought to have reversed their migration, moving outward and significantly shaping the final configuration of the solar system, including the formation of the asteroid belt and the orbital characteristics of the outer planets. This complex migration pattern is believed to have played a crucial role in the overall architecture of the solar system we observe today.
• Explain how the Grand Tack model helps explain the relatively small sizes of the inner terrestrial planets and the distribution of material in the asteroid belt and Kuiper Belt.
  • The Grand Tack model suggests that the inward migration of Jupiter created a barrier in the protoplanetary disk, preventing the inner terrestrial planets from accreting more material and growing larger. This helps explain why the inner planets, such as Mercury, Venus, Earth, and Mars, are relatively small compared to the gas giants. Additionally, the outward migration of Jupiter and Saturn is thought to have played a significant role in the distribution of material in the asteroid belt and Kuiper Belt. The model proposes that the gas giants' migration cleared and reorganized the material in these regions, contributing to the observed characteristics of the asteroid belt and Kuiper Belt.
• Evaluate the potential impact of the Late Heavy Bombardment on the early solar system and how the Grand Tack model may help explain this event.
  • The Late Heavy Bombardment, a period of increased impact cratering in the inner solar system, is believed to have had a significant impact on the early solar system. The Grand Tack model suggests that the migration of the gas giants, particularly Jupiter and Saturn, may have triggered this event. As the gas giants moved inward and outward, their gravitational interactions with the protoplanetary disk and the planetesimals within it may have destabilized the orbits of these small bodies, leading to an increased rate of impacts on the inner planets. The Grand Tack model provides a framework for understanding how the complex migration patterns of the gas giants could have contributed to the Late Heavy Bombardment, which in turn may have had important implications for the early evolution and habitability of the inner solar system planets.

Related terms

Migration: The process by which a planet's orbit changes over time, often moving inward or outward in the protoplanetary disk due to interactions with the disk material.

Protoplanetary Disk: The rotating circumstellar disk of dense gas and dust surrounding a young newly formed star, from which planets are believed to develop.

Planetesimal: The building blocks of planets, small rocky or icy bodies that form in the protoplanetary disk and eventually collide and accrete to form larger planetary bodies.